Question

Write down in sequence the main steps of plant breeding. What is its importance?

Answer 1

Plant breeding is the genetic improvement of the crop in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant. It is the process in which two genetically dissimilar varieties are purposely crossed to produce a new hybrid variety. As a result, characteristics from both parents can be obtained in the hybrid plant variety. The various steps involved in plant breeding are as follows:

(i) Collection of genetic variability- Genetic variability from various wild varieties, species and relatives of crop species are collected to maintain the genetic diversity of a species. Germplasm collection is the entire collection of the diverse alleles of a gene in a crop.

(ii) Evaluation of germplasm and selection of parents- The germplasm collected is then evaluated to identify plants with desirable combination of characters. The selected plants with the desired genes are then used as parents in plant breeding experiments and are multiplied by the process of hybridization.

(iii) Cross-Hybridization among Selected Parents- Cross Hybridization combines the desirable characters present in two different parents to produce hybrids. It is a time consuming and tedious job as one has to ensure that the pollen grains collected from the male parent reach the stigma of the female parent. It is not certain that the hybrids would combine desired characters.

(iv) Selection of superior hybrids- It involves selection of those plants that have the desired character combination among the progeny of the hybrids. The selection process through scientific evaluation yields plants that are superior to both the parents. The selected progenies are then self-pollinated for several generations to ensure homozygosity.

(v) Testing, release, and commercialization of new cultivars- The selected progenies are evaluated for characters such as yield, resistance to diseases, performance, etc. Testing of hybrid variety is done in farmer's field after evaluation. Release of tested material is done in bulk after selection and certification.

Importance of Plant Breeding:

1) Plant breeding has played an important role in enhancing food production.

2) More than 200 varieties of crops have been developed.

3) Disease resistance in plants has been introduced through breeding.

4) Plants with increased tolerance to environmental stresses, such as salinity, extreme temperatures, drought, etc.

5) High yield and improved quality of crop plants.